Ju52 fuel tank level indicators

[FeuerFliegen]

Based on every time I select a certain amount of fuel, and then look at what the fuel gauge indicators read, I feel that they are not accurate.

 

Just now I selected 500L.  The left wing indicator reads 300L; the right reads 400L.  I've tried this same test for all kinds of different fuel amounts and it always reads around 200L above what it actually has.

 

If I am reading this wrong, please educate me on how I should read it.